Generally, a process for manufacturing a semiconductor is largely divided into a front-end process and a back-end process. The front-end process, which is a fabrication process, is a process for forming an integrated circuit pattern on a wafer. The back-end process, which is an assembly process, is a process for forming an integrated circuit package by dividing the wafer into a plurality of chips, connecting a conductive lead or ball to each chip so as to provide electrical path to external devices and then molding the chips with epoxy, etc.
Prior to performing the assembly process, an electrical die sorting (EDS) process for testing the electrical characteristics of each chip is carried out. Defective chips are discriminated during the EDS process. Of the defective chips, reparable chips are repaired and irreparable chips are removed. As a result, it is possible to save time and cost in the following assembly process.
Such EDS process is performed in a probe station. The probe station usually consists of a probe chuck on which the wafer to be tested is seated and a test head having a probe card. A plurality of probes are provided on the probe card, wherein the probes electrically contact pads provided on the respective chips on the wafer so that they can check whether the corresponding chips are defective.
As the semiconductor technology develops, more chips are formed on a single wafer in order to reduce the manufacturing cost and improve the productivity. Recently, with the realization of a 300 mm wafer process, the increase in the number of chips per wafer is accelerated. Therefore, the development of the large area probe card becomes important in the wafer test field.
The conventional probe card for testing the large area wafer may be categorized into the substrate type and the block type from the vantage point of the space transformer. The substrate type, which is a type providing a plurality of probes 102 on a space transformer 101, for example, a ceramic substrate, with a size corresponding to the wafer to be tested (FIG. 1), has advantages in facilitating the subsequent assembly of the space transformer and stably maintaining the probe alignment. However, unlike a general ceramic substrate, the ceramic substrate for the space transformer, which is a substrate having metal lines for providing electrical connection between the probe and the circuit board, is difficult to fabricate. Therefore, the fabricating cost is high. The problem of the ceramic substrate for the space transformer becomes more serious as the area of the substrate increases. At present, the production of a ceramic substrate for the space transformer corresponding to a 300 mm wafer has not been made yet.
Meanwhile, the block type is a type fabricating the large area probe card by dividing the area to be tested into multiple blocks 202, mounting the plurality of probes 203 on the respective blocks 202 and then precisely aligning the respective blocks 202 on a block fixing frame 201, as shown in FIG. 2. Considering the fabricating process, the block type has an advantage that it is possible to replace only the corresponding block when a problem occurs during the fabricating process or during the use. However, as the area to be tested increases, the number of blocks and the length of block to be precisely aligned are increased, too. Therefore, it has the problems that much time is spent to precisely align the blocks in addition to the fact that the alignment of the blocks may deteriorate during the test.